TRANSVASCULAR AND URINARY LEAKAGE OF ALBUMIN IN ATHEROSCLEROTIC AND HYPERTENSIVE MEN

Increased urine albumin is associated with atherosclerotic disease and predicts cardiovascular morbidity and mortality in nondiabetic popula tions. This finding is frequently postulated to reflect the impact of atherosclerotic damage on glomerular and systemic capillary permeabili ty, an interesting but as yet untested hypothesis. The transcapillary escape rate of albumin (TERalb, the 1-hour decline rate of intravenous I-125-albumin, a measure of capillary macromolecular permeability), a lbuminuria, lipid levels, echocardiographic wall thickness, and insuli n responses to oral glucose were measured in 30 untreated dipstick-neg ative lean men and clinically stable atherosclerotic peripheral vascul ar disease; tolerance to oral glucose was a requirement for inclusion in the study. Because hypertension per se might influence TERalb, the sample included either normotensive (n=18, 118+/-6/72+/-7 mm Hg) or hy pertensive (n=12, 141+/-7/84+/-6 mm Hg by 24-hour blood pressure monit oring) arteriopathic patients; 11 normal age- and gender-matched subje cts (121+/-7/76+/-5 mm Hg) were used as control subjects. TERalb was h igher in patients (10.7+/-3.2 versus 7.4+/-1.7%/h, P<0.013), a differe nce that persisted after postload glucose, insulin, and lipid levels w ere accounted for by covariance analysis; atherosclerosis and hyperten sion together did not further impair vascular permeation to albumin. I n contrast with TERalb, albuminuria was elevated only in the hypertens ive subgroup; the 2 variables showed no relationship, even when the da ta were analyzed separately in normotensive and hypertensive subgroups . Urine albumin correlated positively with 24-hour blood pressure and wall thickness. Thus, systemic capillary permeability is altered in no ndiabetic atherosclerotic patients independently from blood pressure l evels, but this abnormality is not reflected by proportionate changes in albuminuria.